Writing in 2000, the political scientist Charles Murray made a rash prediction he may now regret. "The story of human nature, as revealed by genetics and neuroscience, will be conservative in its political [shape]." The American poor would turn out to have significantly different genes to the affluent: "This is not unimaginable. It is almost certainly true." Almost certainly false, more like.

Instead, the Human Genome Project is rapidly providing a scientific basis for the political left. Childhood maltreatment, economic inequality and excessive materialism seem the main determinants of mental illness. State-sponsored interventions, like reduced inequality, are the most likely solutions.